Publications
2004
Rangan P, Masquida B, Westhof E, Woodson S A
Architecture and folding mechanism of the Azoarcus Group I Pre-tRNA Article de journal
Dans: J Mol Biol, vol. 339, no. 1, p. 41-51, 2004, ISBN: 15123419, (0022-2836 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: Azoarcus/enzymology/*genetics Base Sequence Binding Sites Exoribonucleases/metabolism Hydroxyl Radical/metabolism Introns/*genetics Magnesium/chemistry Models, Bacterial/*chemistry/genetics/*metabolism RNA, Ile/chemistry/*genetics Substrate Specificity Support, Molecular Molecular Sequence Data *Nucleic Acid Conformation RNA Precursors/*genetics RNA Splice Sites/genetics RNA Splicing RNA, Non-U.S. Gov't Support, P.H.S., Transfer, U.S. Gov't, Unité ARN, WESTHOF
@article{,
title = {Architecture and folding mechanism of the Azoarcus Group I Pre-tRNA},
author = {P Rangan and B Masquida and E Westhof and S A Woodson},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15123419},
isbn = {15123419},
year = {2004},
date = {2004-01-01},
journal = {J Mol Biol},
volume = {339},
number = {1},
pages = {41-51},
abstract = {Self-splicing RNAs must evolve to function in their specific exon context. The conformation of a group I pre-tRNA(ile) from the bacterium Azoarcus was probed by ribonuclease T(1) and hydroxyl radical cleavage, and by native gel electrophoresis. Biochemical data and three-dimensional models of the pre-tRNA showed that the tRNA is folded, and that the tRNA and intron sequences form separate tertiary domains. Models of the active site before steps 1 and 2 of the splicing reaction predict that exchange of the external G-cofactor and the 3'-terminal G is accomplished by a slight conformational change in P9.0 of the Azoarcus group I intron. Kinetic assays showed that the pre-tRNA folds in minutes, much more slowly than the intron alone. The dependence of the folding kinetics on Mg(2+) and the concentration of urea, and RNase T(1) experiments showed that formation of native pre-tRNA is delayed by misfolding of P3-P9, including mispairing between residues in P9 and the tRNA. Thus, although the intron and tRNA sequences form separate domains in the native pre-tRNA, their folding is coupled via metastable non-native base-pairs. This could help prevent premature processing of the 5' and 3' ends of unspliced pre-tRNA.},
note = {0022-2836
Journal Article},
keywords = {Azoarcus/enzymology/*genetics Base Sequence Binding Sites Exoribonucleases/metabolism Hydroxyl Radical/metabolism Introns/*genetics Magnesium/chemistry Models, Bacterial/*chemistry/genetics/*metabolism RNA, Ile/chemistry/*genetics Substrate Specificity Support, Molecular Molecular Sequence Data *Nucleic Acid Conformation RNA Precursors/*genetics RNA Splice Sites/genetics RNA Splicing RNA, Non-U.S. Gov't Support, P.H.S., Transfer, U.S. Gov't, Unité ARN, WESTHOF},
pubstate = {published},
tppubtype = {article}
}
Self-splicing RNAs must evolve to function in their specific exon context. The conformation of a group I pre-tRNA(ile) from the bacterium Azoarcus was probed by ribonuclease T(1) and hydroxyl radical cleavage, and by native gel electrophoresis. Biochemical data and three-dimensional models of the pre-tRNA showed that the tRNA is folded, and that the tRNA and intron sequences form separate tertiary domains. Models of the active site before steps 1 and 2 of the splicing reaction predict that exchange of the external G-cofactor and the 3'-terminal G is accomplished by a slight conformational change in P9.0 of the Azoarcus group I intron. Kinetic assays showed that the pre-tRNA folds in minutes, much more slowly than the intron alone. The dependence of the folding kinetics on Mg(2+) and the concentration of urea, and RNase T(1) experiments showed that formation of native pre-tRNA is delayed by misfolding of P3-P9, including mispairing between residues in P9 and the tRNA. Thus, although the intron and tRNA sequences form separate domains in the native pre-tRNA, their folding is coupled via metastable non-native base-pairs. This could help prevent premature processing of the 5' and 3' ends of unspliced pre-tRNA.